physiology mcqs.docx

1、physiology mcqs1. Cell membranesA. contain relatively few protein moleculesB. are impermeable to fat-soluble substancesC. in some tissues permit the transport of glucose at a greater rate in the presence of insulinD. are freely permeable to electrolytes but not to proteinsE. have a stable compositio

2、n throughout the life of the cell2. The primary force moving water molecules from the blood plasma to the interstitial fluid isA. active transportB. cotransport with H+C. facilitated diffusionD. cotransport with Na+E. filtration3. Second messengersA. are substances that interact with first messenger

3、s outside cellsB. are substances that bind to first messengers in the cell membraneC. are hormones secreted by cells in response to stimulation by another hormoneD. mediate the intracellular responses to many different hormones and neurotransmittersE. are not formed in the brain4. The resting membra

4、ne potential of a cellA. falls to zero immediately when Na+-K+ ATPase in the membrane is inhibitedB. is usually equal to the equilibrium potential for Cl-C. is usually equal to the equilibrium potential for K+D. is usually equal to the equilibrium potential for Na+E. is markedly altered if the extra

5、cellular Na+ concentration is increased5. Proteins that are secreted by cells areA. not synthesized on membrane bound ribosomesB. initially synthesized with a signal peptide or leader sequence at their C terminalC. found in vesicles and secretory granulesD. moved across the cell membranes by endocyt

6、osisE. secreted in a form that is larger than the form present in the endoplasmic reticulum6. Osmosis isA. movement of solvent across a semipermeable membrane from an area where the hydrostatic pressure is high to an area where the hydrostatic pressure is lowB. movement of solute across a semipermea

7、ble membrane from an area in which it is in low concentration to an area in which it is in high concentrationC. movement of a solute across a semipermeable membrane from an area in which it is in high concentration to an area in which it is in low concentrationD. movement of solvent across a semiper

8、meable membrane from an area in which it is in low concentration to an area in which it is in high concentrationE. movement of solvent across a semipermeable membrane from an area in which it is in high concentration to an area in which it is in low concentration7. Deuterium oxide and insulin are in

9、jected into a normal 30-year-old man. The volume of distribution of deuterium oxide is found to be 42 L and that of insulin 14 L.A. The mans intracellular fluid volume is about 14 LB. The mans intracellular fluid volume is about 28 LC. The mans plasma volume is about 7 LD. The mans interstitial flui

10、d volume is about 9 LE. The mans total body water cannot be determined from these data8. Which of the following diseases is due to a mutation in the mitochondrial genome?A. Cystic fibrosisB. Lebers hereditary optic neuropathyC. Nephrogenic diabetes insipidusD. Familial male precocious pubertyE. Hirs

11、chsprungs disease9. Which of the following receptors does not span the cell membrane 7 times?A. -Adrenergic receptorB. RhodopsinC. 5-HTIC receptorD. Mineralocorticoid receptorE. LH receptor10. Which of the following acts directly on the nucleus to produce physiologic effects?A. IL-1B. Growth hormone

12、C. CortisolD. DopamineE. Estradiol1. The action potential of a neuronA. is initiated by efflux of Na+B. is terminated by efflux of K+C. declines in amplitude as it moves along the axonD. results in a transient reversal of the concentration gradient of Na+ across the cell membraneE. is not associated

13、 with any net movement of Na+ or K+ across the cell membrane2. Which of the following has the slowest conduction velocity?A. A fibersB. A fibersC. A fibersD. B fibersE. C fibers3. A man falls into a deep sleep with one arm under his head. This arm is paralyzed when he awakens, but it tingles, and pa

14、in sensation in it is still intact. The reason for the loss of motor function without loss of pain is that in the nerves to his arm,A. A fibers are more susceptible to hypoxia than B fibersB. A fibers are more sensitive to pressure than C fibersC. C fibers are more sensitive to pressure than A fiber

15、sD. sensory nerves are nearer the bone than motor nerves and hence are less affected by coolingE. sensory nerves are nearer the bone than motor nerves and hence are less affected by pressure4. Which part of a neuron has the highest concentration of Na+ channels per square millimeter of cell membrane

16、?A. DendritesB. Cell body near dendritesC. Initial segmentD. Axonal membrane under myelinE. None of the above5. Which of the following statements about nerve growth factor is not true?A. It is made up of three polypeptide subunitsB. It is found in high concentration in the submandibular salivary gla

17、nds of female miceC. It is necessary for the growth and development of the sympathetic nervous systemD. It is picked up by nerves from the organs they innervateE. It is present in the brain6. The action potential of skeletal muscleA. has a prolonged plateau phaseB. spreads inward to all parts of the

18、 muscle via the T tubulesC. causes the immediate uptake of Ca2+ into the lateral sacs of the sarcoplasmic reticulumD. is longer than the action potential of cardiac muscleE. is not essential for contraction7. The functions of tropomyosin in skeletal muscle includeA. sliding on actin to produce short

19、eningB. releasing Ca2+ after initiation of contractionC. binding to myosin during contractionD. acting as a relaxing protein at rest by covering up the site where myosin binds to actinE. generating ATP, which it passes to the contractile mechanism8. The cross-bridges of the sarcomere in skeletal mus

20、cle are made up ofA. actinB. myosinC. troponinD. tropomyosinE. myelin9. The contractile response in skeletal muscleA. starts after the action potential is overB. does not last as long as the action potentialC. produces more tension when the muscle contracts isometrically than when the muscle contact

21、s isotonicallyD. produces more work when the muscle contracts isometrically than when the muscle contacts isotonicallyE. decreases in magnitude with repeated stimulation10. Gap junctionsA. are absent in cardiac muscleB. are present but of little functional importance in cardiac muscleC. are present

22、and provide the pathway for rapid spread of excitation from one cardiac muscle fiber to anotherD. are absent in smooth muscleE. connect the sarcotubular system to individual skeletal muscle cells11. Which of the following is not synthesized in postganglionic sympathetic neurons?A. L-DopaB. DopamineC

23、. NorepinephrineD. HistamineE. Acetylcholine12. Fast inhibitory postsynaptic potentials (IPSPs)A. are a consequence of presynaptic inhibitionB. interact with other fast and slow potentials to move the membrane potential of the postsynaptic neuron toward or away from the firing levelC. can be produce

24、d by an increase in Na+ conductanceD. can be produced by an increase in Ca2+ conductanceE. occur in skeletal muscle13. Initiation of an action potential in skeletal muscle by stimulating its motor nerveA. requires spatial facilitationB. requires temporal facilitationC. is inhibited by a high concent

25、ration of Ca2+ at the neuromuscular junctionD. requires the release of norepinephrineE. requires the release of acetylcholine14. Which of the following is a ligand-gated ion channel?A. VIP receptorB. Norepinephrine receptorC. GABAA receptorD. GABAB receptorE. Metabotropic glutamine receptor15. Which

26、 of the following is most likely not to be involved in production of LTP?A. NOB. Ca2+C. NMDA receptorsD. Membrane hyperpolarizationE. Membrane depolarization16. Which of the following synaptic transmitters is not a peptide, polypeptide, or protein?A. Substance PB. Met-enkephalinC. -EndorphinD. Serot

27、oninE. Dynorphin17. Activation of which of the following receptors would be expected to decrease anxiety?A. Nicotinic cholinergic receptorsB. Glutamate receptorsC. GABAA receptorsD. Glucocorticoid receptorsE. 1-Adrenergic receptors18. Which of the following receptors is coupled to a heterotrimeric G

28、 protein?A. Glycine receptorB. GABAB receptorC. Nicotinic acetylcholine receptor at myoneural junctionD. 5-HT3 receptorE. ANP receptor19. Which of the following would not be expected to enhance noradrenergic transmission?A. A drug that increases the entry of arginine into neuronsB. A drug that enhan

29、ces tyrosine hydroxylase activityC. A drug that enhances dopamine -hydroxylase activityD. A drug that inhibits monoamine oxidaseE. A drug that inhibits norepinephrine reuptake1. Which of the following is not primarily a function of blood plasma? A. Transport of hormones B. Maintenance of red cell si

30、ze C. Transport of chylomicrons D. Transport of antibodies E. Transport of O2 2. A hematocrit of 41% means that in the sample of blood analyzed A. 41% of the hemoglobin is in the plasma B. 4l% of the total blood volume is made up of blood plasma C. 4l% of the total blood volume is made up of red and

31、 white blood cells and platelets D. 4l% of the hemoglobin is in red blood cells E. 4l% of the formed elements in blood are red blood cells 3. In normal human blood A. the eosinophil is the most common type of white blood cell B. there are more lymphocytes than neutrophils C. the iron is mostly in hemog1obin D. there are more white cells than red cells E. there are more platelets than red cells 4. Lymphocytes A. all originate from the bone marrow after birth B. are unaffected by hormones C. convert to monocytes in response to antigens D. interact with eosinophils to